Pipe inspection systems are frequently employed for determining the presence and location of obstructions in pipes, sewers, conduits, and the like. Existing pipe inspection systems may typically include a video or still camera mounted inside a rugged camera head, coupled to the distal or remote end of a resilient flexible push-cable, and a reel or drum for paying out the push-cable during use, and for rewinding the push-cable for stowage.
During inspection, it is often necessary to slowly advance a camera head down the length of a pipe to ensure a comprehensive inspection with precise data capture. Conversely, when the inspection has concluded, it is desirable to quickly withdraw the camera head from the pipe, and wind the push-cable into a compact unit for storage and transport. Although it may be desirable to quickly retract the push-cable after use, push-cables are generally configured to be rigid when deployed (e.g., a push-cable tends to straighten out to a linear shape to support being pushed through a pipe after being stored in a rounded shape when spooled on a reel), which may cause the push-cable to rapidly and uncontrollably feed out when being deployed.
Thus, there are situations where it is desirable to provide a user with variable resistance in such a system (e.g., more friction or operator loading during deployment or pay-out, less friction or loading during retraction or pay-in). Some existing pipe inspection systems provide variable resistance by using a manually adjustable friction brake that is mechanically associated with the rotatable mounting of the cable storage drum on the stand. However, manually adjustable friction brakes create problems due to complexity of operation and design, as well as unreliability.
Accordingly, there is a need in the art to address the above-described as well as other problems.